Guide housing for rotary drill drive



SRLH RGUM May 19, 1959 E. W. HURD GUIDE HOUSING FOR ROTARY DRILL DRIVE v2 shets-sneet 1.

Filed Aug. 5, 1955 W am m l m Arf s s. a s@ a a. N

May 19, 1959 E. w. HURD 2,887,299

GUIDE HOUSING FOR ROTARY DRILL DRIVE Filed Aug. 3 1955 A 2 Sheets-Sheet 2 Inventor EY'C W. Hurd nited States Patent GUIDE HOUSING FOR ROTARY DRILL DRIVE Eric Wilson Hurd, Pendleton, Salford, England, assignor to F. Taylor & Sons (Manchester) Limited, Salford, England, a British company Application August 3, 1955, Serial No. 526,150 'Claims priority, application Great Britain August 7, 1954 2 Claims. (Cl. 2S5-47) This invention relates to drill units for machines for drilling rock faces and the like and is particularly, though not exclusively, applicable to a drill unit for the machine described in the specification of our co-pending application for patent No. 526,149, now Patent No. 2,867,412.

As is well known, drill units are potentially dangerous to operating personnel, by reason of the rotating drill rod, with which it is only too easy for clothing to become engaged. Drill units with enclosed drills are, of course, known, and because they have a guide for the drill rod they also have advantages over some other constructions.

Such drill units are mounted at the outer end of a long jib and have to combine strength with lightness, the strength being required in the casing to withstand torsional stresses of driving of the drill. It is well known that an ideal section for a drill unit casing would be cylindrical as giving the required torsional strength but, unless the cylinder wall is relatively very thin and therefore vulnerable to damage by indentation, its torsional strength as well as its bending resistance would far exceed practical requirements. Also, an imperforate cylinder would have the disadvantage that they progress of the drill cannot be seen from outside, nor is lateral access possible to the internal mechanism as may be desirable or even necessary. To lighten such casing and at the same time provide lateral visibility and access to the internal mechanism pierced lightening holes could be provided in the length of such casing, but the cost of such operation in a cylinder of say ten to twelve inches in diameter and about twelve feet long, would be considerable.

The object of the present invention is to provide an improved construction of drill unit, particularly as regards the housing or casing therefor in the light of the above observations.

According to the present invention there is provided a drill unit comprising a housing or casing, of generally tubular shape, built up from a plurality of longitudinal elements in which lightening apertures have been formed by a pressing or like operation before assembly.

In a preferred embodiment of the invention the housing or casing is generally octagonal in cross-section and includes a pair of abutting channel members in the sides of which are a plurality of relatively large lightening apertures having peripheral stiifening flanges and providing useful access to as well as visibility of the internal mechanism. The two channel members may conveniently be joined by fish plates welded or otherwise secured thereto over the longitudinal abutting edges thereof.

The invention will be described further, by way of example, with reference to the accompanying drawings in which:

Fig. 1 is a side elevation of a -drill unit according to the invention, certain parts being omitted to illustrate more clearly the internal mechanism.

Fig. la isasection on line la-la of Fig. 1.

'2,887,299 Patented May 19, 1959 ice Fig. 2 is an elevation similar to Fig. l showing the external parts in more detail,

Fig. 3 is a section on the line III, III of Fig. 1, on an enlarged scale,

Fig. 3a is a section on line 3a-3a of Fig. l, and

Fig. 4 is an enlarged cross-sectional side elevation, a detail of the motor and carriage.

In the accompanying drawings, the drill housing 10 is octagonal in shape, twelve inches in depth between two faces and ten inches in width. It is constructed from two longitudinal channel members 11 each measuring twelve feet in length, their longitudinal edges abutting in the centre of the top and bottom of the casing where they are bolted together, such bolts passing through fish platesV (hereinafter referred to) having tapped holes therein. Such channel members 11 may be formed in a rolling mill, or otherwise and, except for a central section 12 of about two feet in length, their sides other than the top and bottom sides are perforated by punching to form circular apertures 13 and 14. In the vertical sides ofthe channel members 11 the apertures 13 are about four inches in diameter at six-anda-'half inch centres whilst the apertures 14 are two inches in diameter at three-and-a-quarte-r inch spacing. In forming each of these apertures an outwardly standing edge bevel 1S is formed to give stiliness, as can easily be done in a punching operation before joining the channel sections together.

The channels 11 are held together by use of U-shaped guide channels or lish plates 19, through which pass bolts 19b. If necessary, the ends of the bolts are smoothed to provide a smooth surface within l'ishplates 19.

At the central section 12 aforesaid the housing is strengthened by a surrounding octagonal sleeve 16 carrying trunnions 17 to engage complementary bearings in forked arms of a bracket attached to one end of a jibV of the drilling machine (not shown).

f Socketed in the rear end of the housing 10 is an electric motor 18 for driving a drill rod and feed mechanism (not shown) while within the housing and secured to the top and bottom faces are U-shaped guide channels 19 adapted for guiding a drill carriage 23. These guide channels 19 serve as ish plates through which pass the aforementioned bolts, this construction serving to give adequate strength to the housing 10. Coupled to the output shaft 20a of a reduction gear 20 embodied inthe electric motor 18, which is secured to the end of the housing 10, is a combined drive shaft and feed screw 21 which, at the other end, is journalled in an end piece 22 xed in such end of the housing 10. A drill carriage 23 has a body part which resembles the headstock of a lathe and has upper and lower slides 24 (see Fig. 3) located in the guide channels 19 aforesaid.

The casing of .motor 18 is provided with integrally formed ribs 18a having thereon, at positions corresponding to the angularly disposed portions of the channels 11, thickened-up parts 18b having flats thereon. The parts 18b are drilled and tapped to receive bolts 18e` which pass through suitably positioned holes in channels 11.

Within the carriage 23 is journalled a shaft 27 carrying at its outer end a drill chuck or socket 25. Also within the carriage is a drill pinion 26, which pinion meshes with a driving pinion 28 slidably located for longitudinal movement on the drive shaft and feed screw 21, the driving pinion 23, at the same time being keyed to the shaft 21 by a keyway 29 so as to rotate therewith. Thus, rotation of the drive shaft and feed screw 21 causes rotation both of the driving pinion 28 and the drill pinion 26, and also of the chuck 25.

Coaxial with the drill pinion 26 and adjacent thereto is a reversing wheel 30 carried upon a reversing shaft 31 slidably located in the carriage 23. This reversing wheel 30 has dogs 32, 33 at each face thereof, the dogs 32 on one face being adapted in one position of the reversing shaft to engage with similar dogs 34 on the drill pinion 26, whilst the dogs 33 on the other face are adapted in another lposition of the reversing shaft 31 to engage stationary dogs 35 on the carriage housing 23. It will be evident` therefore that according to the position of the reversing shaft 31, the reversing wheel 30 will either be in engagement with the drill pinion 26 to rotate therewith, or it will be in engagement with the carriage housing and so constrained against rotation.

The reversing wheel meshes vwith a drill feed wheel 36 which is journalled into the carriage and located on the drive shaft and feed screw 21, a thread being provided on the feed wheel 36 to engage a two-start helical groove or thread 37 extending along the shaft 21. Thus, when the feed wheel 36 is rotated relatively to the shaft 21 the carriage 23 is moved in one or other direction along the shaft 21. The sizes of the Adriving and drill pinions 28, 26 and the reversing and feed wheels 30, 36 are so chosen that, when the reversing wheel 30 is in engagement with the drill pinion 26, a slight increase in gearing the motor is energized, kicks and causes the clutch operating rod 43 to move. The drill motor 18 has onephase which operates a current relay. The current relay is not operated on full load but cornes into operation on 125% full -load and this operation closes the relay to cause actuation of the motor 49 in the correct sense and to displace `the clutch in one or other direction to cause either forward or reverse movement of the drill carriage 23. When the load on the drill reaches a preset critical point, torque reactor 49 causes rotation of sprocket 48 which in turn actuates chain 45. The'chain, through lever 44, rod 43, and box 42 operates clutch 38 to reverse the drill.

What I claim is:

1. A drill unit having a housing comprising two longitudinal channel members arranged in abutting relationship so that said housing is octagonal in' cross section p there being, in said channel members a plurality of lightening apertures having peripheral stiffening flanges, a

is obtained so that the feed wheel 36 rotates slightly faster than the driving pinion 28 when the shaft 21 is rotated, and the carriage moves forwardly along the shaft.

If, however, the shaft 21 is rotated and the reversing wheel 30 is brought into its position with the dogs 33 engaging the dogs on the carriage housing so that the feed wheel 36 cannot rotate, then the rotation of the shaft in the now stationary feed wheel 36 causes the carriage 23 to move rearwardly, at a comparatively fast speed along the shaft 21.

A suitable clutch mechanism indicated generally at 38 is provided for moving the reversing shaft 31 between the two positions described, whereby the drill can be advanced or returned as desired. Details of the clutch operating mechanismy are to be found in co-pending application Serial No. 526,151, filed August 3, 1955.

The end piece 22 is provided with a drill steady 39 in the form of a rod which has on its outer end a serrated face plate 40 which, in use, is brought into contact with the Vrock face to be drilled. A spring 41 is provided on the rod and normally urges the face plate 40 outwardly of the housing 10 and is compressed when the face plate 40 abuts the rock face, thereby holding rigidly inposition the end of the housing 10 and effectively preventing the latter, together with the drill, from vibrating excessively thereby reducing the risk of breaking the drill during its initial cut.

Secured to the drill carriage 23 is a clutch actuating box 42 which latter, through a clutch operating rod 43 and a lever 44 is secured to an endless chain 45 which extends over the length of the housing 10 and is carried by a pair of sprockets 46 (one only of which is shown) located one at each end of the housing 10. One run of the chain is located in conduits 47 outside the housing and between the conduits 47 is secured, forwardly of the sleeve 16, a chain sprocket 48 around which passes the outer run of the chain 45. A torque reactor 49 comprises in fact a three-phase motor which is adapted to reverse the clutch in the carriage 23. The chain 45, when `drill carriage slidably mounted within said housing and a rotatable drill chuck mounted on said carriage and fish plates" extending longitudinally within the housing and secured over the abutting edges of said channel members, which sh plates serve as guides for said drill carriage, including said rotatable drill chuck, means being provided for` rotating said drill chuck and advancing and returning'said carriage comprising a motor mounted at one end of said housing, a combined feed screw and drive shaft coupled to said motor extending longitudinally through said housing and said carriage, a shaft journalled in said carriage having a chuck mounted thereon at one end and a drill pinion at its other end, a driving pinion slidably mounted .on said drive shaft and feed screw and constrained to rotate therewith meshing with said drill pinion, a reversing wheel displaceably mounted in said carriage and capable of selective engagement either with the drill pinion or said carriage, a feed wheel mounted on said drive shaft and feed screw and engaging with the screw of the latter, said reversing wheel in engagement with said feed Wheel and means for selectively engaging said reversing wheel with said drill pinion and said carriage.

2. A drill unit having a housing comprising two longitudinal channel members arranged in abutting relationship so that said housing is octagonal in cross-section, there being a plurality of lightening apertures in said channel members having peripheral stiifening flanges, fish plates extending longitudinally within the housing and secured over the abutting edges of said channel members, which fish plates serve as guides for a drill carriage including a rotatable drill chuck mounted on the drill carriage, a motor mounted at one end of said housing, a combined feed screw and drive shaft coupled to said motor and extending longitudinally through said housing and through said drill carriage, and means for rotating said drill chuck from said feed screw and drive shaft.

References Cited in the le of this patent UNITED STATES PATENTS 2,388,720 Wright Nov. 13, 1945 2,423,682 Castle July 8, 1947 2,474,726 Source .lune 28, 1949 s l n 

